Primary immunodeficiency diseases arise due to genetic abnormalities of one or more genes important in human immunity. There are over 80 different immune defects, with an estimated incidence of 1:500 to 1:500,000. The incidence of individual diseases has been difficult to assess. Various countries have made attempts to enumerate cases of primary immunodeficiency; from this, it appears that while there may be racial differences in the incidence of different immune defects, these diseases are present in all populations studied. In published studies, there has been a noticeable lack of minority subjects, perhaps resulting from under- diagnosis of these diseases in these populations. Delayed diagnosis leads to increased morbidity and inflated global medical costs; ultimately this delay results in increased mortality. The hypothesis of this demonstration and education proposal is that primary immune deficiency diseases may not be recognized in minority and economically disadvantaged individuals, and that this hypothesis can be tested in a large urban hospital containing multi- racial patient populations, by targeting disease codes associated with immuno- deficiency. To test this hypothesis, we have constructed a computer screening method that we will use as an instrument to survey our hospital, using combinations of disease codes commonly related to the occurrence of congenital immune deficiency. From this we will ascertain the potential prevalence and type of such diseases, race, sex and age of these subjects and the location in which such subjects are likely to receive medical care. In a pilot study, 2.9% of inpatients and 2.0% of outpatients had two or more codes suggestive of immunodeficiency; these subjects were significantly more often Hispanic, and more likely to have Medicaid than patients without these codes (p = .OO1). In our second aim, the Clinic/Hospital Emergency Room locations where such individuals are concentrated, will be targeted, using a nursing professional to verify prospectively, by specific testing, if immune defects that can be identified. By further refining these codes, in association with the age of subject and the number of medical encounters, we will construct a method of discrminant analysis that may be used to more rapidly locate individuals with selected immune defects. A final goal is to create, pilot, and implement a program of community and provider education, to target the specific affiliated medical facilities and other outreach locations that would most benefit from educational services, diagnostic and treatment resources pertinent to congen- ital immune defects.